Testing for deficiencies ?

[f-e]

Are there any plant tissue analysis options for the home grower?

I have looked briefly at mass spectrometers, realising it's what I likely need, but I don't really have a clue. Are there any chemical methods to find the concentrations of anything worth knowing?

We can find good info like the percentage of things present in leaf tissue, but how would I get from an ill looking leaf, to a piece of paper listing what was in it.

If only it were legal, I could have a lab run the tests. I could even do so on healthy looking tissue, every day, if it were cost effective. Recognising deficiencies that haven't shown themselves, but could still be improved upon.

Big operations are surely doing this.


I'm happy to go off down the rabbit hole here of diffraction measurement of different light frequencies. Maybe we could build something..

 

[GOT_BUD?]

Any place that can do plant tissue analysis will work. The trick slownickle taught me was to dry out the leaf material very well and crumble it up (the lab will do this anyways to test). Remove any veining from the product, and send it in as comfrey.

 

[f-e]

If you were moving towards a Calcium deficiency, it would show along the veins.

I have had a look (rather than a guess) at the mass spec, and making one would take forever.

I may of been mislead by sites offering all manner of test kits that are almost right, but then you realise their idea of a professional is a Dowser.
This looks good at a glance https://www.lifeworkpotential.com/products/Common-Elements-Metals-And-Minerals-Test-Kit
But I'm not sure that it's any kind of test. It looks like a hoax site.

The local shop will do samples, but never have and don't know the price. Moving the conversation forward leads to glances over my shoulder out the window. They are concerned as I am, that a self appointed police man, with too much time on their hands, will know with 100% accuracy, just what the sample is. It's not worth it.

 

[cyberneticsteer]

ag lab

ag lab

I work as an ag consultant and frequently use plant tissue analysis to diagnose problems. My consultant agency has a lab they use, and there are a lot of other ag labs out there. If possible, send in a sample of the most mature fan leaves from a good plant, and some from bad, then you have something to compare it to. If you are unable to do that, let me know maybe I can help. I got some numbers from hemp plants last year I can share. With the proliferation of hemp I wouldnt worry too much about legality, just say its hemp. I know our lab techs dont give a shit.
Good luck!

 

[f-e]

Thank you for the reply. Unfortunately I'm in the UK.

A deficiency study published the control plants foliage content.

N 4.28%
P 0.43%
K 2.85%
Ca 3.73%
Mg 0.61%
S 0.41%
Mn 29.40 mg·kg−1
B 58.58 mg·kg−1
Cu 4.65 mg·kg−1
Fe 111.75 mg·kg−1
Mo 1.46 mg·kg−1
Zn 25.33 mg·kg−1

 

[cyberneticsteer]

Cool, what study? I recently came across a great article on deficiencies https://www.researchgate.net/public...tion_of_Nutrient_Disorders_of_Cannabis_sativa

BTW for anyone, the KIS organics marijuana cultivation podcast is fantastic!!

 

[cyberneticsteer]

woops just saw the other thread where you reference the same article! Its interesting stuff for sure!

 

[f-e]

Perhaps just some stoned mutterings, but if I had a sample of what they got to drink, and also what ran off, then I could see what they ate from it, almost exactly.

I only need get the feed bottles looked at once. So it's just run-off samples to look at after that. If I were just growing one thing, I would like to chart usage throughout a whole crop, as both a diagnostic tool when things are running out, and as a way to look at adjusting the feed inline with it's identified needs. I would be especially interested in the transition from grow to flower.

There are 7 part feeds out there, to give a feed profile more tailored to the plants needs. Perhaps the data used to decide this schedule is online?

 

[G.O. Joe]

Perhaps just some stoned mutterings, but if I had a sample of what they got to drink, and also what ran off, then I could see what they ate from it, almost exactly.

Maybe they eat things they don't need and it's not clear that high percentages are always desired or when exactly they are.

There is a different way to do water analysis. Ashing, dissolving in nitric acid and/or HCl, boiling with distilled water to remove the acid, and diluting. The relative proportions of most things not N can then be determined whichever way water analysis is available.

 

[f-e]

Hmm. I certainly eat things I don't need to. I guess if plants didn't, then an overfeed would be very rare indeed. I think some good info could be gained though, even now I'm not so stoned

I will have to look up ashing. It's crossed my path before and seems self explanatory.
Thank you

 

[cyberneticsteer]

I think theres reason to believe too much nitrogen can be harmful for a plant. Cells grow to fast and become weak and susceptible to disease and pests. There is also a "luxury consumption" of elements in the abundance of them, like over eating. Its not necessarily detrimental, but just a bit wasteful.
I like your idea of measuring the intake and outflow concentrations of nutrients! Imagine if you could have some computer adjust the fertilizer as needed, so the crop gets exactly what it needs!

 

[f-e]

I think theres reason to believe too much nitrogen can be harmful for a plant. Cells grow to fast and become weak and susceptible to disease and pests. There is also a "luxury consumption" of elements in the abundance of them, like over eating. Its not necessarily detrimental, but just a bit wasteful.
I like your idea of measuring the intake and outflow concentrations of nutrients! Imagine if you could have some computer adjust the fertilizer as needed, so the crop gets exactly what it needs!

That would be great, and I imagine it's what big companies are doing. As you can't pump out all that waste, it needs conditioning for use again. Though maybe they tanker it away to another company that does the recycling. Turning it into a base product again, to be sold to anybody.

It's an expensive bit of kit, that needs a room, and staff with degree's.

I'm against the wall with related needs. I'm putting together some auto dosing kit. But what I dose changes almost daily. There is a predictable pattern, that some analysis could really help iron out. Then I need some fancy timing software though, to run the various dosing pumps a little bit different each day. I keep looking at lab choices, and may have to do a grow in something inert, to give baseline figures I can then work over to get back in coco. I'm of the calculator generation though. I can't spell Arduino and I know for a fact that Raspberry Pie is edible. I tried to make a basic timer and found I didn't have a lifetime spare to complete it. I know my limits...